Flat mechanical electric commutators

ABSTRACT

An improved flat or cylindrical mechanical electric commutator with neutral segments ( 4 ) between the current carrying segments which allow the current carrying carbon brushes ( 11, 12, 13, 14 ) in a brush holder ( 7 ) to pass from a negative current carrying segment to a positive current carrying segment or the opposite charge current in the base of the commutator without allowing the face or any part of the carbon brush to touch both the negative and positive segments in the base of the commutator at the same time, resulting in the switching of the electric current to an energized coil of an electric motor, electrical generator or electric apparatus or device, at predetermined intervals and times to suit the design requirements of the energized coil, electric motor of the stepper, brushless DC and switched design, electric generator or electric apparatus or device, while the commutator can accommodate single phase electrical circuits, double phase electrical circuits, three phase electrical circuits or any number of faces as required by the design specifications, all operating independently of each other.

The following statement is a full description of this invention,including the best Method of performing it known to me:

The normal “carbon brush on a round segmented copper armaturecommutator” only changes the direction of the electrical current twicefor every single rotation of the round segmented copper armature. Thenumber of times the direction of the electrical current can be changed,can be increased by increasing the number of the carbon brushes inpairs. One to carry the positive current, and one to carry the negativecurrent. One of the main problems with this type of commutator is thatthe carbon brushes can touch both the negative charged segment of thearmature, and the positive charged segment of the armature at the sametime, causing it to arc. This can cause premature wearing out of thecarbon brushes, and damage to the energized coil if the armature is notallowed to rotate. The new non-classical electric motors, like thestepper motors,brushless DC motors and switched reluctance motors weremade possible by advances in semi-conductor technology, because of theirreliance on position sensing, and numerous switching of the direction ofthe current for every single rotation of the rotor.

One of the objects of this invention is to provide a simple, effectiveand low cost carbon brush commutator, which can do the same operation,of switching the electrical current, as an electronic commutator, withthe advantages that a person can physically see to control the timing ofthe switching of the electrical current, and if it is not working, whatis wrong, with the added advantage that the carbon brushes can beindividually replaced if worn out, unlike an electronic commutator,which requires specialized testing equipment to determine whichcomponent is faulty, with the usual replacing of the whole electroniccontroller, as it is not cost effective to repair.

In the Drawings:

FIG. 1. Shows a flat single phase commutator base, with three rings ofcopper material in bedded in a round piece of insulating material, whichhas a larger diameter than the outer copper ring. The inner copper ringis continuous. The outer copper ring is also continuous. The middlecopper ring is broken up into segments, in groups of four, for each timethe electrical current is to be switched, some are connected to theouter ring, some are connected to the inner ring, and some are neutral,surrounded by insulation material.

FIG. 2. Shows a cross section A, B, of FIG. 1, view of the flatcommutator with the three copper rings positioned in the insulationmaterial and a carbon brush and brush holder positioned at 90 degrees tothe flat commutator.

FIG. 3. Shows the base, and the first stage of a sequence for a singlephase electric motor, and the position of one set of carbon brushes on asingle phase commutator. With both carbon brushes positioned over“neutral” segments.

FIG. 4. Shows the base and the second stage, with the position of on setof carbon brushes on a single phase commutator. With one carbon brushpositioned over the “positive” segment, while the other carbon brush ispositioned over the “negative” segment.

FIG. 5. Shows the base and the third stage, with the position of one setof carbon brushes on a single phase commutator. With both carbon brushespositioned over “neutral” segments.

FIG. 6. Shows the base and the fourth stage, with the position of oneset of carbon brushes on a single phase commutator. With the carbonbrush which was positioned over the “positive” in stage two, nowpositioned over the “negative”, and the other carbon brush which waspositioned over the “negative” in stage two, now positioned over the“positive” segment. The sequence started in FIG. 3 continues.

FIG. 7. Shows the base, and the positions of the carbon brushes on thefirst phase of a three phase commutator, and their connection to theenergized coils on a six pole, three phase electric motor.

FIG. 8. Shows the base and the positions of the carbon brushes on thesecond phase of a three phase commutator, and their connection to theenergized coils on a six pole, three phase electric motor.

FIG. 9. Shows the base and the positions of the carbon brushes on thethird phase of a three phase commutator, and their connection to theenergized coils on a six pole, three phase electric motor.

FIG. 10. Shows an alternative method to the flat base commutator, whichis a cylindrical commutator with slip rings, and segments radiatingoutwards, with carbon brushes positioned on the circumference.

FIG. 11. Shows one of the methods to manufacture the base of the flatcarbon brush commutator, without having to inlay the copper segmentsinto the insulation material individually.

FIG. 12. Shows stage one, of one of the methods to secure and fix inposition the outside copper ring, the center ring segments and the innercopper ring.

FIG. 13. Shows stage two, of one of the methods to secure and fix inposition the outside copper ring, the center ring segments and the innercopper ring.

FIG. 14. Shows stage three, of one of the methods to secure and fix intoposition the outside copper ring, the center ring segments and the innercopper ring, with the copper backing sheet removed, leaving the ringsand segments securely imbedded in the insulating material, preventingthem from moving.

FIG. 15. Shows an alternative method to secure and fix in position theoutside copper ring, the center ring segments and the inner copper ring,by pressing the base shape into a sheet of copper material, with thebottom of the highest part, higher than the top of the lowest part, sothat when the top material, or backing sheet is removed, the rings andsegments are positioned into the insulating material.

FIG. 16. Shows the three stages of an alternative method referred to inFIG. 15, with flared sections at the base of the pressing for lockingthe sheet into the insulating material, to prevent them from moving.

This invention in its simplest form consists of referring to FIG. 1, anouter ring 2, an center segmented ring 36, and an inner ring 3, ofcopper attached to a flat round piece of insulation material 38, whichhas a larger diameter than the outer copper ring 2. The inner copperring 3 is continuous. The outer copper ring 2, is also continuous. Themiddle copper ring 36, is broken up into segments 4,5,6, in groups offour, for each time the electrical current is to be switched. The firstsegment of the group is independent or neutral 4, and is not connectedto either the outer 2 or inner ring 3, and has insulation material 38,on four sides to prevent shorting with the other segments 5,6. Thesecond segment 6, of the group is connected to the outer ring 2, but notto the inner ring 3, or a neutral segment 4, but has insulation material38, on three sides to prevent shorting with the other segments 5. Thethird segment 4, of the group is also independent or neutral 4, and isnot connected to either the outer 2, or inner rings 3. This segment hasinsulation material 38, on four sides to prevent shorting with the othersegments 5, 6. The fourth segment 5, of the group is connected to theinner ring 3, but not to the outer ring 2, or neutral segments 4, buthas insulation material 38, on three sides to prevent shorting with theother segments 6. It is not important whether they are called second andfourth segments, provided there is a neutral segment 4, between everysegment that is joined to the inner 3 or outer 2 copper electric currentcarrying slip rings.

FIG. 2. A carbon brush holder 7, FIG. 3 with four carbon brushes11,12,13,14, is fitted FIGS. 3.,4.,5.,6., so that one contacts the outercopper ring 2, one contacts the inner copper ring 3 and there are twocarbon brushes 12, 13, on the center copper ring 36, one in front of theother. FIG. 4. They are positioned so that one is on the segment 13,connected to the outer ring 2, and one is on the segment 12, connectedto the inner copper ring 3. The segments 4,5,6, are of equal length, andthe size or surface area of the carbon brushes 8, in contact with thecopper rings 2,3, and segments 36, is governed by the size of theneutral copper segments 4. The operation of the flat mechanical electriccommutator is as follows. The base of the commutator rotates 1, and thecarbon brushes 8, are fixed in a set position in the carbon brush holder7, made of insulated material 38. To start with in FIG. 4 the frontcarbon brush 13 in the center ring segment is touching the copper ringsegment 6, connected to the (+) positive electrical charge outer ring 2,so it also will be a (+) positive connection.

While the carbon brush 12, touching the copper ring segment 5, in thecenter ring connected to the (−) negative electrical charge inner ring3, will be a (−) negative connection. As the commutator rotates FIG. 5.,the front carbon brush 13, moves from the (+) positive segment 6, overthe neutral segment 4, FIG. 6., to the (−) negative segment 5, and nowbecomes a (−) negative connection. The rear carbon brush 12, which wasover the (−) negative segment 5, now has move over the neutral segment4, then over the (+) positive segment 6, and now becomes a (+) positiveconnection. The neutral copper segments 4, allow the carbon brush 8, tomove from the (−) negative electrical charged segment 5, to the positive(+) electrical charged segment 6, without shorting (touching both (−)negative and (+) positive segments 5, 6, at the same time).

The width of the carbon brushes 8, is such that it can not bridge the(−) negative segment 5, over the neutral segment 4, to the (+) positivesegment 6. If the neutral segment 4, where not there, the gap betweenthe negative segment 5, and the positive segment 6, would need to be tolarger than the width of the carbon brush 8, for the carbon brush 8, tooperate effectively. It would have to leave the negative segment 5,before it touched the positive segment 6, to prevent shorting, and couldget trapped in the gap between negative 5, and positive segments 6.Causing the carbon brush 8, to break or suffer excessive wear FIG. 7.shows a single phase setup with the connections to an improved electricmotor, illustrated at top of page, in which the carbon brush 12, isconnected to the windings on the energized coil 15, which are connectedto the windings on the energized coil 18, which are connected to thecarbon brush 13, to complete the circuit. The windings are arranged, soboth outer faces on the energized coils 15, 18, have the same magneticpole.

In FIGS. 7., 8., by positioning a second set of brushes FIG. 8. 32, 33,on the center ring segments 36, on the base of the commutator 1, andconnect carbon brush 32 to the windings of the energized coil 17 whichis connected to the windings on energized coil 20, which is connected tothe carbon brush 33 to complete the circuit. The windings are arranged,so both outer faces on the energized coils 17,20, are the same magneticpole, and are the magnetic pole to suit the design of the motor. Theplacement of the carbon brushes 32,33, so that they actuate theswitching at a different, but predetermined time make it is possible touse this flat copper carbon brush system for two phase motorcommutation.

Like wise, FIG. 9. by positioning three sets of carbon brushes 12,13:32,33: and 34,35, on the center ring segments, this system can beused for a three phase motor commutation. It can be used for any numberof phase commutation, depending on requirements, simply be putting thenumber of carbon brush sets on the center ring segments 36, as describedfor a single phase, but by varying the switching times. In someapplications it is not necessary to have the slip rings 2,3, if the baseof the commutator 1, is the stationary component, and the carbon brushholder 7, is the moving part, and moves with the energized coils15,16,17,18,19,20, the electrical current can be supplied directly theappropriate copper segments 36. There may be other suitable materials tocopper, so the reference to copper, covers all suitable materials, andis not limited to copper.

FIG. 10, shows a round commutator 1, with slip rings 2,3, which areconnected to segments 5,6, there are neutral segments 4, which insulated38, and are not connected to either positive or negative electricalcurrent. Carbon brushes 8, are positioned around the circumference, toachieve the same desired switching as already described for a flatcopper base, carbon brush commutator. It is important that the neutralsegments 4, are positioned between the active segments 5,6, and that thewidth of the carbon brush 8, is less than the width of the neutralsegment 4, to prevent arcing of the carbon brush 8. It is not importantwhether the lead 10, for the carbon brush 8 comes from the top or sideof the carbon brush 8. In some applications it is not necessary to havethe slip rings 2,3, if the base of the commutator 1, is the stationarycomponent, and the carbon brush holder 7, is the moving part, and moveswith the energized coils 15,16,17,18,19,20. The electrical current canbe supplied directly the appropriate copper segments 36. There may beother suitable materials to copper, so the reference to copper, coversall suitable materials, and is not limited to copper. This type ofcommutator is much simpler to make as once the number of switchingoperations is determined, a copper mold FIG. 11. 37, with a raisedsegments 25, standing proud (like little hills on a flat plain)connected by a thin backing plate layer of copper 26. The raisedsegments 25, could have a tubular protrusion 27, (similar to a semitubular rivet) on top of the segment 25, which would be pressed tospread out over the top of the segment standing proud, 28 (similar to asemi tubular rivet with its end sprayed over). This copper molding 37,has insulation material 38, around all the segments standing proud 25,and incorporating some fastening or locating shape 27. The backing plate26, is removed leaving the raised segments 25, locked in place.

The attached sprayed tubular protrusions 27, 28, ensure the coppersegments 25, can not move in the insulating material base 38. The carbonbrush holder 7, is molded of a suitable material like Bakelite, with thenumber and position of the carbon brushes 8, predetermined to suit theelectric motor switching design requirements. This method of manufactureis much simpler and cost effective than the conventional carbon brush onround commutator, or electronic commutator currently in use. Thoseskilled in the art would know that not all the embodiment of thisdescription may be needed to make the improved flat mechanical electriccommutator. The materials may be changed to suit new materialsdeveloped. The number of groups of four segments 36, will vary to suitthe number of switching operations required. It is not necessary to haveall the carbon brushes 8, in the one holder 7, but it is desirable, asit guarantees the distance between the two center copper ring carbonbrushes. It should be noted that the carbon brush connections 9, fromthe leads to the energized coils can be switched to suit designrequirements as described in the second phase, due to the inside face ofthe permanent magnets 21,22,23,24, in the stator, being the oppositemagnetic pole.

I claim:
 1. An Improved Flat or Cylindrical mechanical ElectricCommutator with neutral segments between the current carrying segmentswhich allow the current carrying carbon brushes in a brush holder topass from a negative current carrying segment to a positive currentcarrying segment or the opposite charge current in the base of thecommutator without allowing the face or any part of the carbon brush totouch both the negative and positive segments in the base of thecommutator at the same time, resulting in the switching of the electriccurrents to an energized coil of an electric motor, electrical generatoror electric apparatus or device, at predetermined intervals and times tosuit the design requirements of the energized coil, electric motors ofthe stepper, brushless DC and switched reluctance designs, electricgenerator or electric apparatus or device, while the commutator canaccommodate single phase electric circuits, double phase electricalcircuits, three phase electrical circuits or any number of phases asrequire by the design specifications, all operating independently ofeach other.
 2. The Improved Flat or Cylindrical Mechanical ElectricCommutator of claim 1, wherein flat continuous inner or outer slip ringsare connected to some of the segment in a central segmented ring, toeffectively switch the electrical charge being received by the centralcarbon brushes passing over the center ring segments.
 3. The ImprovedFlat or Cylindrical Mechanical Electric Commutator of claim 1, whereasthe carbon brush holder and brushes rotate around a stationary singlesegmented copper ring in the base or armature of the commutator.
 4. Amethod for producing the segmented base or armature of an Improved Flator Cylindrical Mechanical Electric Commutator of claim 1, by pressing aflat sheet of copper material or molding the raised required parts incopper or other suitable material, molding insulating material on threesides of the pressing or molding, leaving the raised parts clean andthen removing the raised section to leave the required copper segmentsfirmly fixed in the molded insulated material, held in by spreadportions on the base of the segments, which make the base wider than themiddle section of the segments.
 5. A method for producing the segmentedbase or armature of an Improved Flat or Cylindrical Mechanical ElectricCommutator of claim 1, by pressing a flat sheet of copper material ormolding the raised required parts in copper or other suitable material,molding insulating material on three sides of the pressing or molding,leaving the raised parts to act as a backing sheet, which when removed,leave the required copper segments firmly fixed in the molded insulatedmaterial, held in by spread portions of semi tubular rivets on the baseof the segments, which make the base of the rivets wider than the semior tubular section of the rivet.